512 THE DIVING BIRDS — PYGOPODES. 



which are a rictal plate and a broad, curved, posteriorly truncate shield covering the lateral base 

 of the mandible. Forehead ornamented by an upright recurved tuft of slender feathers, the tips of 



which overhang the bill ; head farther ornamented by a postocular series of slender white 

 filamentous feathers. Plumage plain — uniform dusky above, gray below. 

 A single species (.S'. cristatellus) belongs to this genus, as here restricted. 



Simorhynchus cristatellus. 



THE CRESTED AUK. 



Alca eristatdla, Pall. Spic. Zool. V. 1769, 20, pi. 3 and pi. 5, figs. 7, 8, 9. — Gmel. S. N. I. ii. 



1788, 552, no. 7. 

 Simorhynchus cristatellus, " Merrem," Bonaf. Compt. Rend. XLII. 1856, 774. — Cites, Pr. Ac 



Nat. Sri. Philad. 1868, 37 ; Key, 1872, 34'2 ; Check List, 1873, no. 622 ; ed. 2, 1SS2, no. 859 ; 



Elliott's Alaska, 1875, 206. — Ridgw. Norn. X. Am. 1!. 1881, no. 748. 

 Phaleris cristatellus, Stephens, Gen. Zool. XIII. 1S25, 47, pi. 5. — Cass, in Baird's 11. N. Am. 



1S58, 866. — Baird, Cat. X. Am. I'.. 1859, no. 719. 

 Phaleris superciliatn, Aim. Orn. Biog. pi. 402 ; B. Am. VII. 1844, pi. 437 (not Mormon superdliosa, 



Licht., = Alca pygmcea, Cm.). 

 Vria dubia, Pali. Zoog. Rosso-As. II. 1826, 371, pi. 87 (= young). 

 Simorhynchus dubius, Coues, Pr. Ac Nat. Sci. Philad. 1868, 40. 

 Alca tetracula, Pali.. Spic. Zool. V. 1760, 23, pi. 4, and pi. 5, figs. 10, 11, 12. — Gmel. S. N.I. ii. 



17S8, 552, no. 8. 

 Phaleris tetracula, ''ass. in Baird's P». N. Am. 1S5S, 907. — R.uisn, Cat. N. Am. R. 1859, no. 720. 

 Simorhynchus tetraculus, Coues, Pr. Ac. Nat. Sri. Philad. 1868, 43, fig. 9; Key, 1S72, 342. 



Hab. Coasts and islands of the North Pacific, from Kadiak and Unalashka through the 

 Aleutian chain to Kamtschatka and Northern Japan ; north to Prybilof Islands. 



Sp. Char. Adult, breeding-dress: Basal portion of the bill covered with complicated super- 

 numerary pieces, tin- most conspicuous of which is a detached semicircular concave plate situated 

 just above the rictus. Upper parts dusky blackish ; lower parts uniform smoky gray, shading 

 insensibly into the blackish of the upper parts. On the forehead a curled crest of narrow dusky 

 brown feathers, curved forward in the greater part of a circle ; behind the eve, extending thence 

 back over the auriculars, a streak of narrow acicnlar white leathers. Bill bright orange-red, the 

 end pale horn-color; iris white ; legs and feet dusky in the dried skin. Adult, in winter (= Alca 

 tetracula, PALLAS) : Similar in plumage, even to the nest and whit.- auricular filaments ; Put Pill 

 very different, owing to the loss of the supernumerary basal pieces, being much smaller, smooth, 

 and destitute of the rictal shield, the broad expansion of the mandibular rami and nasal shield ; 



